Infrared lamp adjusting circuit, law enforcement recorder and control method of infrared lamp

Abstract

The application discloses an infrared lamp adjusting circuit, a law enforcement recorder and a control method of an infrared lamp. The infrared lamp adjusting circuit comprises an infrared lamp assembly, an ambient light detection circuit, a distance detection circuit and an infrared lamp control circuit. The ambient light detection circuit is used for detecting the light intensity in the environment and outputting a light intensity detection signal. The distance detection circuit is used for detecting the distance between a measured target and the infrared lamp assembly and outputting a distance detection signal. The infrared lamp control circuit is connected with the ambient light detection circuit and the distance detection circuit respectively. The infrared lamp control circuit is used for outputting a control signal to control the operation of the infrared lamp assembly and adjusting the brightness of the infrared lamp assembly according to the light intensity detection signal and the distance detection signal. The application aims at solving the problem that the infrared lamp cannot automatically adjust the brightness of the infrared lamp and always works with high power consumption in different scenes (for example, overcast day, night, early morning or evening or indoor or outdoor).

Description

Technical Field

[0001] This invention relates to the field of law enforcement recorders, and in particular to an infrared lamp adjustment circuit, a law enforcement recorder, and a control method for infrared lamps. Background Technology

[0002] Law enforcement recorders are widely used for recording law enforcement officers in various indoor and outdoor locations. In order to meet the lighting requirements of wide-angle cameras in dark environments or other working environments so that law enforcement recorders can achieve clear recording effects, it is usually necessary to illuminate the target with infrared lights. The infrared light enters the lens to form an image after being reflected by the object. Therefore, infrared lights play a crucial role in law enforcement recorders.

[0003] Currently, law enforcement recorders have two methods for activating infrared lights. One method involves manual activation via a button. However, for violations that are quickly forgotten, manual activation not only delays enforcement time but also carries the risk of forgetting to turn on the infrared lights, resulting in the inability to collect and preserve evidence in a timely manner. The other method involves automatic activation based on the ambient light intensity detected by a photosensitive element. In this case, if clothing or accessories obstruct the photosensitive element, it can cause false activation of the infrared lights, increasing the power consumption of the law enforcement recorder. Furthermore, while law enforcement recorders can operate in cloudy weather, at night, early morning, late afternoon, or in environments with fluctuating light levels, the brightness of the infrared lights cannot be adjusted according to environmental changes, resulting in the infrared lights operating at high current and high brightness continuously, leading to significant power consumption and heat generation. Summary of the Invention

[0004] The main objective of this invention is to propose an infrared lamp adjustment circuit. This invention aims to solve the problem that infrared lamps cannot automatically adjust their brightness in different scenarios (e.g., cloudy days, nighttime, early morning / evening, or indoor / outdoor environments) and thus continue to operate with high power consumption.

[0005] To achieve the above objectives, the present invention provides an infrared lamp adjustment circuit, which includes:

[0006] Infrared light assembly;

[0007] An ambient light detection circuit is used to detect the light intensity in the environment and output a light intensity detection signal.

[0008] A distance detection circuit is used to detect the distance between the target being measured and the infrared lamp assembly, and output a distance detection signal;

[0009] An infrared lamp control circuit is connected to the ambient light detection circuit and the distance detection circuit respectively. The infrared lamp control circuit is used to control the operation of the infrared lamp assembly and adjust the brightness of the infrared lamp assembly based on the light intensity detection signal and the distance detection signal.

[0010] In one embodiment, the infrared lamp control circuit includes:

[0011] The main control chip is connected to the ambient light detection circuit and the distance detection circuit respectively. The main control chip is used to output corresponding control signals according to the light intensity detection signal and the distance detection signal.

[0012] A PWM conversion circuit, the input terminal of which is connected to the main control chip, is used to convert the received control signal into a PWM control signal for output.

[0013] A switching circuit is provided, wherein the input terminal of the switching circuit is connected to the output terminal of the PWM conversion circuit, and the output terminal of the switching circuit is connected to the infrared lamp assembly. The switching circuit controls the brightness of the infrared lamp assembly according to the PWM conversion control signal.

[0014] In one embodiment, the PWM conversion circuit includes a power input terminal, a switching transistor, a first resistor, and a second resistor;

[0015] The first end of the first resistor is the input terminal of the PWM conversion circuit, the second end of the first resistor is connected to the controlled terminal of the switching transistor, the output terminal of the switching transistor is connected to the power input terminal, the input terminal of the switching transistor is grounded, and the common terminal of the switching transistor and the power input terminal is the output terminal of the PWM conversion circuit.

[0016] In one embodiment, the switching circuit includes a driver chip, a third resistor, a fourth resistor, and a first capacitor;

[0017] The PWM dimming control pin of the driver chip is connected to the output terminal of the PWM conversion circuit. The feedback pin of the driver chip is connected to the first terminal of the third resistor. The second terminal of the third resistor is interconnected with and grounded to the ground pin of the driver chip. The power supply pin of the driver chip, the first terminal of the first capacitor, and the first terminal of the fourth resistor are interconnected. The second terminal of the first capacitor is grounded. The second terminal of the fourth resistor is connected to the input terminal of the infrared lamp assembly. The output terminal of the infrared lamp assembly is connected to the drive pin of the driver chip.

[0018] The feedback pin of the driver chip is used to control the maximum output current value of the infrared lamp assembly according to the resistance value of the third resistor.

[0019] The PWM dimming control pin of the driver chip is used to control the conduction or de-conduction of the driver pin of the driver chip according to the high level or low level output of the PWM control signal, and when the driver pin of the driver chip is on, the duty cycle is output according to the PWM control signal to change the brightness of the infrared lamp assembly.

[0020] In one embodiment, the infrared lamp assembly includes a first infrared lamp and a second infrared lamp;

[0021] The anode of the first infrared lamp is the input terminal of the infrared lamp assembly, the cathode of the first infrared lamp is connected to the anode of the second infrared lamp, and the cathode of the second infrared lamp is the output terminal of the infrared lamp assembly.

[0022] In one embodiment, the ambient light detection circuit includes an ambient light detection sensor or an ambient light detection chip.

[0023] In one embodiment, the distance detection circuit includes a distance detection sensor or a distance detection chip.

[0024] The present invention also includes a law enforcement recorder, comprising the aforementioned infrared lamp adjustment circuit.

[0025] The present invention also includes a method for controlling an infrared lamp, applied to the aforementioned infrared lamp adjustment circuit or the aforementioned law enforcement recorder, the method for controlling the infrared lamp comprising the following steps:

[0026] Acquire ambient light intensity detection signals and distance detection signals between the target and the infrared lamp assembly;

[0027] The system outputs a PWM control signal based on the ambient light intensity detection signal and the distance detection signal to control the brightness of the infrared lamp assembly.

[0028] In one embodiment, the step of outputting a PWM control signal based on the received ambient light intensity detection signal and distance detection signal to control the brightness of the infrared lamp assembly includes:

[0029] When the ambient light intensity value is determined to be the ambient light intensity value when the infrared light assembly is turned on, and the distance detection signal indicates that there is no obstruction between the target and the infrared light assembly, the infrared light assembly is controlled to turn on; and,

[0030] Based on the ambient light intensity value, a corresponding PWM control signal is output to control the brightness of the infrared lamp assembly.

[0031] In this invention, the infrared lamp adjustment circuit includes an infrared lamp assembly, an ambient light detection circuit, a distance detection circuit, and an infrared lamp control circuit. The ambient light detection circuit detects the light intensity in the environment and outputs a light intensity detection signal. The distance detection circuit detects the distance between the target and the infrared lamp assembly and outputs a distance detection signal. The infrared lamp control circuit is connected to both the ambient light detection circuit and the distance detection circuit. The infrared lamp control circuit controls the operation of the infrared lamp assembly based on the light intensity detection signal and the distance detection signal, and adjusts the brightness of the infrared lamp assembly. This invention utilizes the ambient light detection circuit and the distance detection circuit to collaboratively determine the operating environment of the law enforcement recorder, providing a more accurate understanding of the external environment and enabling precise adjustment of the infrared lamp assembly. This ensures that the camera on the law enforcement recorder maintains good shooting performance under varying light intensities, effectively solving the problem of the infrared lamp on the law enforcement recorder not automatically adjusting its brightness and thus operating at high power consumption in different scenarios (cloudy days, nights, early mornings, evenings, or indoor / outdoor environments). Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 This is a functional module diagram of an embodiment of the infrared lamp adjustment circuit of the present invention;

[0034] Figure 2 This is a circuit diagram of an embodiment of the infrared lamp control circuit of the present invention;

[0035] Figure 3 This is a circuit diagram of another embodiment of the infrared lamp adjustment circuit of the present invention;

[0036] Figure 4 This is a first flowchart of an embodiment of the infrared lamp control method of the present invention;

[0037] Figure 5 This is a second flowchart of an embodiment of the infrared lamp control method of the present invention.

[0038] Explanation of icon numbers:

[0039] label name label name 100 Infrared light assembly 400 Infrared lamp control circuit 200 Ambient light detection circuit 410 PWM conversion circuit 300 Distance detection circuit 420 Switching circuit

[0040] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0045] This invention proposes an infrared lamp adjustment circuit for use in law enforcement recorders.

[0046] Currently, law enforcement recorders have two methods for activating infrared lights. One method involves manual activation via a button. However, for violations that are quickly forgotten, manual activation not only delays enforcement time but also carries the risk of forgetting to turn on the infrared lights, resulting in the inability to collect and preserve evidence in a timely manner. The other method involves automatic activation based on the ambient light intensity detected by a photosensitive element. In this case, if clothing or accessories obstruct the photosensitive element, it can cause false activation of the infrared lights, increasing the power consumption of the law enforcement recorder. Furthermore, while law enforcement recorders can operate in cloudy weather, at night, early morning, late afternoon, or in environments with fluctuating light levels, the brightness of the infrared lights cannot be adjusted according to environmental changes, resulting in the infrared lights operating at high current and high brightness continuously, leading to significant power consumption and heat generation.

[0047] To solve the above problems, refer to Figures 1 to 3 In one embodiment of the present invention, the infrared light adjustment circuit of the present invention is used in a law enforcement recorder, and the infrared light adjustment circuit of the present invention includes:

[0048] Infrared light assembly 100;

[0049] The ambient light detection circuit 200 is used to detect the light intensity in the environment and output a light intensity detection signal;

[0050] The distance detection circuit 300 is used to detect the distance between the target and the infrared lamp assembly 100 and output a distance detection signal.

[0051] An infrared lamp control circuit 400 is connected to the ambient light detection circuit 200 and the distance detection circuit 300, respectively. The infrared lamp control circuit 400 is used to control the operation of the infrared lamp assembly 100 and adjust its brightness based on the light intensity detection signal and the distance detection signal. The infrared lamp control circuit 400 can be a circuit board or a microcontroller that acts as a central control unit, or other programmable logic devices; this is not limited to these specific applications.

[0052] It should be noted that the infrared light assembly 100 can be implemented using one or more combinations of LED infrared lights, array infrared lights, or laser infrared lights. By setting the infrared light assembly 100, the law enforcement recorder can capture objects invisible to the naked eye even in the absence of light, improving the practicality of the law enforcement recorder. It should also be noted that the infrared light assembly 100 can not only operate in dark environments, but in some other embodiments, it can also operate in dark environments such as cloudy days, nights, early mornings, or evenings; no specific limitations are made here. The photosensitive element on the ambient light detection circuit 200 can automatically... The ambient light detection circuit 200 is convenient to use and detects ambient light intensity. Furthermore, to prevent clothing, accessories, or other objects from obstructing the photosensitive element and causing the infrared lamp assembly 100 to automatically turn on, thus wasting energy, the distance detection circuit 300 can detect the distance between the target and the infrared lamp assembly 100 and output a distance detection signal to determine if there is an obstruction. The distance measurement between the target and the infrared lamp assembly 100 can be set as needed, such as the minimum distance between people or between a person and an object. For example, when there is no obstruction, the signal value representing the distance between the target and the infrared lamp assembly 100 output by the distance detection circuit 300 is larger; when there is an obstruction, the signal value representing the distance between the target and the infrared lamp assembly 100 output by the distance detection circuit 300 is smaller. The conditions for activating the infrared light assembly 100 are set according to user needs and are not limited here. For example, if the ambient light detection circuit 200 detects that the light intensity has reached the activation condition, but the distance detection circuit 300 detects an obstruction on the photosensitive element, it indicates that the ambient light near the law enforcement recorder is dim due to the obstruction, causing the ambient light detection circuit 200 to detect the light intensity that has reached the activation condition. To avoid accidental activation, in this embodiment, the infrared light control circuit 400 determines that the law enforcement recorder is obstructed based on the light intensity detection signal and the distance detection signal, and outputs a control signal to turn off the infrared light assembly 100. In this case, the infrared light assembly 100 does not work, thus reducing energy waste by preventing it from activating.When the ambient light detection circuit 200 detects light intensity that meets the activation conditions, and the distance detection circuit 300 detects and outputs a distance detection signal indicating that there are no obstructions on the photosensitive element, it indicates that the surrounding environment is nighttime or the user has entered a dark space, requiring the infrared light to be activated. The infrared lamp control circuit 400 determines that the ambient light is dim based on the light intensity detection signal and the distance detection signal, and outputs a control signal to activate the infrared lamp assembly 100. In addition, the infrared lamp control circuit 400 can also be used to adjust the brightness of the infrared lamp assembly 100 according to the magnitude of the control signal to save power. For example, in environments with fluctuating brightness or alternating light and dark conditions, the brightness of the infrared lamp assembly 100 will adjust according to changes in ambient light intensity after activation. In this way, the infrared lamp assembly 100 will not be continuously activated with high current and high brightness, saving power consumption.

[0053] In the technical solution of the present invention, the ambient light detection circuit 200 and the distance detection circuit 300 are used to jointly determine the usage environment of the law enforcement recorder, so as to more realistically know the external environment of the law enforcement recorder and accurately adjust the infrared light component 100. This can ensure that the camera on the law enforcement recorder has a good shooting effect under different light intensities, and effectively solve the problem that the infrared light component 100 on the law enforcement recorder cannot automatically adjust the brightness of the infrared light in different scenarios (cloudy day, night, early morning or evening, or indoor and outdoor) and thus works with high power consumption.

[0054] In one embodiment of the present invention, reference is made to... Figures 1 to 3 The infrared lamp control circuit 400 includes:

[0055] The main control chip (not shown in the figure) is connected to the ambient light detection circuit 200 and the distance detection circuit 300 respectively. The main control chip is used to output corresponding control signals according to the light intensity detection signal and the distance detection signal.

[0056] A PWM conversion circuit 410 is provided, the input terminal of which is connected to the main control chip. The PWM conversion circuit 410 is used to convert the received control signal into a PWM control signal for output. The PWM conversion circuit 410 can be implemented using a conversion chip or composed of switching devices and resistive elements, etc., without specific limitations.

[0057] A switching circuit 420 is included, with its input terminal connected to the output terminal of the PWM conversion circuit 410 and its output terminal connected to the infrared lamp assembly 100. The switching circuit 420 controls the brightness of the infrared lamp assembly 100 according to the PWM conversion control signal. It should be noted that the switching circuit 420 can be implemented using a separate switch control chip or a driver chip combined with switching elements; no specific limitation is made here. The infrared lamp control circuit 400 can intelligently adjust the brightness of the infrared lamp assembly 100 according to the ambient light, eliminating the need for manual operation and saving energy.

[0058] Specifically, refer to Figures 1 to 3 In one embodiment, the PWM conversion circuit 410 includes a power input terminal VCC, a switching transistor Q1, a first resistor R1, and a second resistor R2. It should be noted that the switching transistor Q1 can be a transistor, a MOSFET, or an IGBT, etc., and no specific limitation is made here.

[0059] The first end of the first resistor R1 is the input terminal of the PWM conversion circuit 410, and the second end of the first resistor R1 is connected to the controlled terminal of the switching transistor Q1. The output terminal of the switching transistor Q1 is connected to the power input terminal VCC, and the input terminal of the switching transistor Q1 is grounded. The common terminal of the switching transistor Q1 and the power input terminal VCC is the output terminal of the PWM conversion circuit 410. In this embodiment, the switching transistor Q1 is implemented using an NPN transistor. The voltage at the power input terminal VCC is 3.3V. Since the infrared lamp control circuit 400 outputs a control signal at the IR_SW_EN terminal... The high level output is 1.8V, while the input level of the switching circuit 420 needs to be above 3V. Therefore, by setting the PWM conversion circuit 410, the brightness of the infrared lamp component 100 can be adjusted by controlling the infrared lamp control circuit 400 to output a high or low level at the control signal output terminal IR_SW_EN. For example, when IR_SW_EN outputs a high level, the switching transistor Q1 is turned on, and the output terminal of the PWM conversion circuit 410 outputs a low voltage; when IR_SW_EN outputs a low level, the switching transistor Q1 is turned off, and the output terminal of the PWM conversion circuit 410 outputs a high voltage.

[0060] Furthermore, in one embodiment, reference is made to... Figures 1 to 3 The switching circuit 420 includes a driver chip U1000, a third resistor R3, a fourth resistor R4, and a first capacitor C1. In this embodiment, the driver chip U1000 is a low-dropout adjustable LED constant current driver chip U1000, specifically model IC_THD5T50, which supports PWM dimming at a maximum frequency of 200KHz, making the dimming range wider.

[0061] The PWM dimming control pin DIM of the driver chip U1000 is connected to the output terminal of the PWM conversion circuit 410. The feedback pin VFB of the driver chip U1000 is connected to the first terminal of the third resistor R3. The second terminal of the third resistor R3 is interconnected with the ground pin GND of the driver chip U1000 and grounded. The power supply pin VCC of the driver chip U1000, the first terminal of the first capacitor C1, and the first terminal of the fourth resistor R4 are interconnected. The second terminal of the first capacitor C1 is grounded. The second terminal of the fourth resistor R4 is connected to the input terminal of the infrared lamp assembly 100. The output terminal of the infrared lamp assembly 100 is connected to the drive pin DRV of the driver chip U1000.

[0062] The feedback pin VFB of the driver chip U1000 is used to control the maximum output current of the infrared lamp assembly 100 according to the resistance value of the third resistor R3; for example, in this embodiment, according to calculation formula I LED =300mV / R3, the output voltage of the feedback pin VFB of the driver chip U1000 is 300mV. When the resistance of the third resistor R3 is 1 ohm, the current flowing through the infrared lamp assembly 100 is 300mA. In other embodiments, the third resistor R3 can be set to other resistance values ​​according to different user needs, which are not specifically limited here.

[0063] The PWM dimming control pin DIM of the driver chip U1000 is used to control the conduction or cutoff of the driver pin DRV of the driver chip U1000 according to the high or low level of the PWM control signal output. When the driver pin of the driver chip U1000 is on, the brightness of the infrared lamp assembly 100 is changed according to the duty cycle of the PWM control signal output. For example, when the ambient light intensity is relatively dim and not due to obstructions, the duty cycle of the PWM control signal output is increased to increase the brightness of the infrared lamp. Conversely, when the ambient light intensity is bright, the duty cycle of the PWM control signal output is decreased to decrease the brightness of the infrared lamp assembly 100. In other words, by adjusting the duty cycle of the PWM control signal output, the current of the infrared lamp can be changed, thereby achieving the purpose of adjusting the brightness. In this way, the infrared lamp assembly 100 will not be constantly operating at high power, thus avoiding wasting electrical energy.

[0064] In this embodiment, refer to Figure 3 The infrared lamp assembly 100 includes a first infrared lamp LED1 and a second infrared lamp LED2;

[0065] The anode of the first infrared LED1 is the input terminal of the infrared lamp assembly 100, the cathode of the first infrared LED1 is connected to the anode of the second infrared LED2, and the cathode of the second infrared LED2 is the output terminal of the infrared lamp assembly 100. In some other embodiments, the infrared lamp assembly 100 may be configured as one infrared lamp, three infrared lamps, or more infrared lamps; no specific limitation is made here.

[0066] In one embodiment, the ambient light detection circuit 200 includes an ambient light detection sensor or an ambient light detection chip, which is specifically set according to user requirements and is not limited here.

[0067] In one embodiment, the distance detection circuit 300 includes a distance detection sensor or a distance detection chip, which can be set according to user requirements and is not limited here.

[0068] Furthermore, in one embodiment, reference Figure 2To reduce the number of components and simplify circuit board wiring and component layout, the ambient light detection circuit 200 and the distance detection circuit 300 can be implemented using a shared circuit. That is, integrating the distance detection circuit 300 and the ambient light detection circuit 200 into the same integrated chip improves the integration level of the law enforcement recorder circuit and reduces the size of the circuit board. Furthermore, integrating the distance detection circuit 300 and the ambient light detection circuit 200 into the same integrated chip reduces the number of peripheral circuits, further reducing the size of the law enforcement recorder circuit board and enabling the law enforcement recorder to become lighter and smaller, while also reducing its cost.The shared circuit includes an ambient light sensor and a proximity detection sensor U1103, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second capacitor C2, and a third capacitor C3. The ambient light sensor and proximity detection sensor U1103 can detect not only ambient light intensity but also the distance between the target and the infrared lamp assembly 100. The ambient light sensor and proximity detection sensor U1103 are of model STK3311-X. Specifically, the power supply terminal VDD of the ambient light sensor and proximity detection sensor U1103... The first terminal of the second capacitor C2 is interconnected with the first terminal of the sixth resistor R6. The second terminal of the sixth resistor R6 is connected to the first power supply terminal VIO28_PMU of the infrared lamp control circuit 400. The first power supply terminal VIO28_PMU is powered by 2.8V. The IIC communication pins SCL and SDA of the ambient light sensor and the proximity sensor U1103 are connected to the communication pins of the infrared lamp control circuit 400, respectively. The ambient light sensor and the proximity sensor U1103 transmit the collected data to the infrared lamp control circuit 400 via the IIC protocol. The lamp control circuit 400 communicates with the ambient light sensor and the proximity sensor U1103. The GND terminals of the ambient light sensor and the proximity sensor U1103 are grounded. The interrupt terminal INT of the ambient light sensor and the proximity sensor U1103 is connected to the VIO18_PMU terminal of the infrared lamp control circuit 400 via the fifth resistor R5. The fifth resistor R5 is an interrupt pull-up pin. With some software programs, the ambient light sensor and the proximity sensor U1103 can be controlled to collect and detect the light intensity in the environment or detect the distance between the target and the infrared lamp assembly 100 at regular intervals. The specific time can be set according to user needs and is not limited here. In addition, the third and fourth pins of the ambient light sensor and the proximity detection sensor U1103 are connected, the fifth pin of the ambient light sensor and the proximity detection sensor U1103 is connected to the first end of the seventh resistor R7, the second end of the seventh resistor R7, the first end of the third capacitor C3 and the VBAT terminal of the infrared lamp control circuit 400 are connected, and the second end of the third capacitor C3 is grounded. It should be noted that the sixth resistor R6 and the seventh resistor R7 are current limiting resistors, and the second capacitor C2 and the third capacitor C3 are filter capacitors.

[0069] The present invention also proposes a law enforcement recorder (not shown in the figure), which includes the infrared lamp adjustment circuit of the above embodiment. The specific structure of the law enforcement recorder is as described in the above embodiment. Since the law enforcement recorder adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0070] This invention also proposes a method for controlling infrared lights, applied to the aforementioned infrared light adjustment circuit or law enforcement recorder. In one embodiment, please refer to... Figures 1 to 5 The infrared lamp adjustment circuit includes an infrared lamp assembly 100, an ambient light detection circuit 200, a distance detection circuit 300, and an infrared lamp control circuit 400. The control method for the infrared lamp includes the following steps:

[0071] Step S10: Acquire ambient light intensity detection signal and distance detection signal between the target and infrared lamp assembly 100;

[0072] Step S20: Output a PWM control signal based on the ambient light intensity detection signal and the distance detection signal to control the brightness of the infrared lamp assembly 100.

[0073] In this solution, the ambient light intensity detection circuit 200 first acquires the ambient light intensity detection signal, and then the distance detection circuit 300 acquires the distance detection signal between the target and the infrared lamp assembly 100. This prevents clothing, accessories, or other objects from obstructing the photosensitive element, causing the ambient light detection circuit 200 to detect an ambient light intensity that meets the conditions for the infrared lamp assembly 100 to turn on, thus avoiding wasted energy. Finally, the infrared lamp control circuit 400 outputs a PWM control signal based on the ambient light intensity detection signal and the distance detection signal to control the brightness of the infrared lamp assembly 100. In other words, even in environments with fluctuating light or darkness, the brightness of the infrared lamp assembly 100 will adjust according to changes in ambient light intensity after it is turned on, rather than maintaining a constant brightness. The infrared light assembly 100 will not be continuously powered on at high current and high brightness, thus saving power consumption. It should be noted that the infrared light assembly 100 can not only work in environments with fluctuating light or light and dark conditions, but also in some other embodiments, it can work in dark environments such as cloudy days, nights, early mornings, or evenings, or even in completely dark environments. No specific limitations are made here. By using the ambient light detection circuit 200 and the distance detection circuit 300 to collaboratively determine the operating environment of the law enforcement recorder, a more accurate understanding of the external environment of the law enforcement recorder can be obtained, and the infrared light assembly 100 can be accurately adjusted. This ensures that the camera on the law enforcement recorder can maintain good shooting results under different light intensities, effectively solving the problem that the infrared light assembly 100 on the law enforcement recorder cannot automatically adjust the brightness of the infrared light in different scenarios (cloudy days, nights, early mornings, evenings, or indoors and outdoors) and thus works with high power consumption.

[0074] In one embodiment, please refer to Figure 5 The step of outputting a PWM control signal based on the received ambient light intensity detection signal and distance detection signal to control the brightness of the infrared lamp assembly 100 includes:

[0075] Step S21: When the infrared light meets the turning condition based on the ambient light intensity value and the preset ambient light intensity value when the infrared light assembly 100 is turned on, and when it is determined based on the distance detection signal that there is no obstruction between the target being measured and the infrared light assembly 100, the infrared light assembly 100 is controlled to turn on.

[0076] Step S22: Based on the ambient light intensity value, output a PWM control signal of corresponding magnitude to control the brightness of the infrared lamp assembly 100.

[0077] First, the infrared light control circuit 400 determines that the infrared light has met the activation conditions based on the ambient light intensity value and the preset ambient light intensity value when the infrared light component 100 is turned on. It also controls the infrared light component 100 to turn on when there are no obstructions between the target and the infrared light component 100, based on the distance detection signal. The preset ambient light intensity value for when the infrared light component 100 is turned on is determined according to user needs and is not limited here. Then, the infrared light control circuit 400 outputs a PWM control signal of corresponding magnitude based on the ambient light intensity value to control the brightness of the infrared light component 100. In other words, when the external environment is dark and the brightness is not due to obstruction by objects, the infrared light component 100 will turn on. When the ambient light dims, the infrared lamp assembly 100 meets the conditions for turning on the infrared lamp. The infrared lamp assembly 100 continuously monitors the ambient light intensity. When the ambient light gradually dims, the infrared lamp control circuit 400 controls the PWM control signal output PWM to gradually increase the duty cycle to increase the brightness of the infrared lamp assembly 100. When the ambient light gradually brightens, the infrared lamp control circuit 400 controls the PWM control signal output PWM to gradually decrease the duty cycle to avoid wasting power. In addition, when the infrared lamp control circuit 400 detects that the ambient light intensity does not meet the conditions for turning on the infrared lamp, it will turn off the infrared lamp assembly 100. In this way, automatic control can be achieved, saving power.

[0078] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An infrared lamp adjustment circuit for use in a law enforcement recorder, characterized in that, include: Infrared light assembly; An ambient light detection circuit is used to detect the light intensity in the environment and output a light intensity detection signal. The distance detection circuit is used to detect the distance between the target being tested and the infrared lamp assembly, and outputs a distance detection signal to determine whether there is an obstruction; The infrared lamp control circuit is used to control the operation of the infrared lamp assembly based on the light intensity detection signal and the distance detection signal, and to adjust the brightness of the infrared lamp assembly. The infrared lamp control circuit includes: The main control chip is connected to the ambient light detection circuit and the distance detection circuit respectively. The main control chip is used to output corresponding control signals according to the light intensity detection signal and the distance detection signal. A PWM conversion circuit, the input terminal of which is connected to the main control chip, is used to convert the received control signal into a PWM control signal for output. A switching circuit includes a driver chip, a third resistor, a first capacitor, and a fourth resistor. The PWM dimming control pin of the driver chip is connected to the output terminal of the PWM conversion circuit. The feedback pin of the driver chip is connected to the first terminal of the third resistor. The second terminal of the third resistor is interconnected with and grounded to the ground pin of the driver chip. The power supply pin of the driver chip, the first terminal of the first capacitor, and the first terminal of the fourth resistor are interconnected. The second terminal of the first capacitor is grounded. The second terminal of the fourth resistor is connected to the input terminal of the infrared lamp assembly. The output terminal of the infrared lamp assembly is connected to the drive pin of the driver chip. The feedback pin of the driver chip is used to control the maximum output current value of the infrared lamp assembly according to the resistance value of the third resistor. The PWM dimming control pin of the driver chip is used to control the conduction or de-conduction of the driver pin of the driver chip according to the high level or low level output of the PWM control signal, and when the driver pin of the driver chip is on, the duty cycle is output according to the PWM control signal to change the brightness of the infrared lamp assembly. The main control chip is also used to output an on signal to the switch circuit when the light intensity detection signal reaches the on condition of the infrared light assembly and when the distance detection signal determines that there is no obstruction between the target being tested and the infrared light assembly; and to output a off signal to the switch circuit when the light intensity detection signal reaches the on condition of the infrared light assembly and the distance detection signal determines that the law enforcement recorder is obstructed, so that the infrared light assembly will not be turned on.

2. The infrared lamp adjustment circuit as described in claim 1, characterized in that, The PWM conversion circuit includes a power input terminal, a switching transistor, a first resistor, and a second resistor. The first end of the first resistor is the input terminal of the PWM conversion circuit, the second end of the first resistor is connected to the controlled terminal of the switching transistor, the output terminal of the switching transistor is connected to the power input terminal, the input terminal of the switching transistor is grounded, and the common terminal of the switching transistor and the power input terminal is the output terminal of the PWM conversion circuit.

3. The infrared lamp adjustment circuit as described in claim 1, characterized in that, The infrared lamp assembly includes a first infrared lamp and a second infrared lamp; The anode of the first infrared lamp is the input terminal of the infrared lamp assembly, the cathode of the first infrared lamp is connected to the anode of the second infrared lamp, and the cathode of the second infrared lamp is the output terminal of the infrared lamp assembly.

4. The infrared lamp adjustment circuit as described in claim 1, characterized in that, The ambient light detection circuit includes an ambient light detection sensor or an ambient light detection chip.

5. The infrared lamp adjustment circuit as described in claim 1, characterized in that, The distance detection circuit includes a distance detection sensor or a distance detection chip.

6. A law enforcement recorder, comprising the infrared lamp adjustment circuit as described in any one of claims 1 to 5.

7. A method for controlling an infrared lamp, applied to the infrared lamp adjustment circuit as described in any one of claims 1 to 5 or the law enforcement recorder as described in claim 6, characterized in that, The method for controlling the infrared lamp includes the following steps: Acquire ambient light intensity detection signals and distance detection signals between the target and the infrared lamp assembly; The system outputs a PWM control signal based on the ambient light intensity detection signal and the distance detection signal to control the brightness of the infrared lamp assembly.

8. The control method for infrared lamps as described in claim 7, characterized in that, The step of outputting a PWM control signal based on the ambient light intensity detection signal and the distance detection signal to control the brightness of the infrared lamp assembly includes: When the ambient light intensity value is determined to be the ambient light intensity value when the infrared light assembly is turned on, and the distance detection signal indicates that there is no obstruction between the target and the infrared light assembly, the infrared light assembly is controlled to turn on; and, Based on the ambient light intensity value, a corresponding PWM control signal is output to control the brightness of the infrared lamp assembly.

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